Development Of Three Wheeler Electric Vehicle With BLDC Motor

International Journal of Pure and Applied Mathematics Volume 114 No. 7 2017, 271-280 ISSN: 1311-8080 (printed version); ISSN: 1314-3395 (on-line version) url: http://www.ijpam.eu Special Issue ijpam.eu Development Of Three Wheeler Electric Vehicle With BLDC Motor B. Sateesh1, Srirama Murthy Bellala2, P. Raviteja3, V. S. V. Satyanarayana4 1Dept of Mechanical Engg, Vignan’s IIT, Visakhapatnam, India 2Dept. of Mechanical Engg., ANITS, Visakhapatnam, India 3Dept of Electrical Engg, Vignan’s IIT, Visakhapatnam, India 4Dept of Mechanical Engg, Miracle Group of Intuitions, Vizianagaram, sateesh india@rediffmail.com1, murthy.bellala@gmail.com2, p.tejaeee@gmail.com3, svajrapuphd@rediffmail.com4 April 14-15, 2017 Abstract Environmental protection and energy issues have most active subject of interest and electric cars with Brushless DC motors are new energy efficient drives in industrial applications. In the present paper control system is designed to develop electric car brushless DC motor and numerical analysis is performed. The results illustrated that the brushless DC motor had good controllability and suitable for the application to the electric car. Key Words:Environmental protection, Energy, Electric car, BLDC motor, MATLAB 1. Introduction Latest advances in permanent magnet materials have resulted 271

International Journal of Pure and Applied Mathematics Special Issue Brushless DC motors are new energy efficient drives and very popular in industrial applications such as automotive, aerospace, industrial automation etc due to its high reliability and efficiency, low maintenance requirements and economy. BLDC motor is electronically commutated and finds numerous applications in motion control [1]. Overcome the challenge of implementing required control functions by new generation of microcontrollers and advanced electronics to make the BLDC motor more practical has [2-4]. Even though three-wheelers are lighter and cost of manufacturing is less, for poorly designed applications this platform is the less forgiving layout. In the present study aimed at ‘Modelling of three wheeler electric cars (tri-car) with BLDC motor to protect the environmental and save energy’[5]. 2. Mathematical Model 2.1 Mathematical model of Three Wheeler Electric Vehicle In the present study mathematical model of three wheeler electric car with BLDC motor is developed. Three wheeler electric vehicles, it is required to identify all forces which affects the dynamic behaviour of the vehicle and to determine the torque produced by forces on the vehicle when vehicle is stopped or in movement. There are several forces acting on the vehicle, but the major forces that affect the vehicle dynamics are static friction, rolling resistance, traction or braking force, aerodynamic drag force. A model of electric vehicle is used to determine the normal reaction on the front and rear wheel. The Parked vehicle dynamics are testing in the different road conditions i.e., level road and an inclined road. L l1 l2 c mg Wf 2Wr Fig. 1: Vehicle dynamics on level road Fig. 2: Parked vehicle on an inclined road 272

International Journal of Pure and Applied Mathematics Special Issue Fig. 3: Accelerating vehicle on an inclined plane Planar static equilibrium equations are W 0 M 0 Planar static equilibrium equations 2 Fx 2 mg Sin 0 Wf 2Wr mg Cos 0 y Wfl1 2Wr l2 2 Fx 2 h 0 Wf 2Wr mg 0 Wfl1 2Wr l2 0 1 (mgl2 cos mgh sin ) L 1 Wr (mgl1 cos mgh sin ) 2L 1 Fx 2 mg sin 2 Wf W f l1 l2 (mg W f ) 0 Wf mgl2 L 1 ( mg W f ) 2 1 l mg Wr ( mg 2 ) 2 L mgl1 Wr L Wr (a) Parked vehicle on plane road (b) Parked vehicle on an inclined road Fx 2 is the braking force applied on wheel. At maximum inclination angle, the F f rWr braking force is proportional to the normal force. Therefore x 2 1 (mgl2 cos M mgh sin M ) L 1 Wr (mgl1 cos M mgh sin M ) 2L f Tan M r (l1 h Tan M ) L f r l1 Tan M L fr h Wf (c) Rear Wheel Braking (d) Front Wheel Braking 273

International Journal of Pure and Applied Mathematics Special Issue f rW f 2 f rWr mg sin M 0 Wf 2Wr mg Cos M 0 W f l1 2Wr l2 ( f rW f 2 f rWr )h 0 Tan M f r (e) Three wheels braking Where, Wf : Normal reaction of front wheel Wr : Normal reaction on rear wheel l1 : Distance of centre of mass in the plane of L : Wheel base front wheel l2 : Distance of centre of mass in the plane of rear wheel : Angle of inclination g : Acceleration due to gravity in m / s 2 a : Acceleration of the vehicle R : Radius of the wheel f r : Rolling friction of the wheel Rr : Rolling resistance force N : Normal force on the wheel NOTE: For achieving maximum acceleration the vehicle must be designed with rear wheel drive and all wheel brake. 2.2 MODELING OF BLDC MACHINE Modelling of BLDC motor is similar to DC motor where two equivalent circuits i.e., electrical and mechanical equations. The main construction difference between BLDC and DC motor is that phase winding of the BLDC motor at the stator side and rotor contains permanent magnet, but in DC motor phase winding is at rotor side and stator contains permanent magnet. La ea Ra a Lb ia eb Rb b Lc ib Rc ec c ic Fig. 4. Three phase Brushless DC motor equivalent circuit For simplicity, the electrical model of one phase can be represented as stator winding, phase k (k a, b or c) is given by the equation di (t ) Vkn (t ) ik Rk Lk k ek (t ) dt 274

International Journal of Pure and Applied Mathematics Special Issue Where, Vkn (t ) - Instantaneous of k-phase voltage, ik (t ) Instantaneous of k-phase current, ek (t ) - Instantaneous of k phase back- EMF voltage, Rk - k phase resistance, Lk - k phase inductance The mathematical model for the BLDC motor voltage equations are as follows by the assuming that the magnet has high sensitivity and rotor induced currents can be neglected and stator resistances of all the windings are equal. Hence there is no change in rotor reluctance with angle. Va R 0 0 ia La Lba Lca ia ea d V 0 R 0 i L b b dt ba Lb Lcb ib eb (1) Vc 0 0 R ic Lca Lcb Lc ic ec The equation of motion is Where, - rotor angular velocity, B - viscous friction, J - moment of inertia, TL - load torque Total torque produced by motor is sum of the torque produced by individual phase The following vehicle parameters are chosen: Mass of the vehicle is 300 kg, Aerodynamic coefficient is 0.3. vehicle front cross sectional area is 2.43 m2 , Air density is 1.225 kg/m3 L 2.6 m, l1 1.6 m , h 0.8 m, J 0.30 kg-m2, R 0.25 m, f r 0.02 The Brushless DC motor drive during speed and torque regulation is developed in MATLAB as shown in the Fig. 5 Discrete, 1e-006 speed Powergui Sp Tm Torque A motor Conv. B C i a Conv. speed A Tem Ctrl 220V 60 Hz motor Ctrl B V dc C Wm Stator current Rotor speed Electromagnetic Torque DC Bus Voltage demux Brushless DC motor drive Fig. 5: Brushless DC Motor Drive during Speed and Torque regulation 3. Simulation Results Design and simulation of BLDC motor drive was done using MATLAB (SIMULINK) and results of simulation parameters are given in TABLE 1. 275 scope

International Journal of Pure and Applied Mathematics Special Issue TABLE 1: Simulation parameters DC Voltage Fundamental frequency Switching frequency Rs 220V 60 Hz 10 kHz 0.2 Ls J B Kb 8.5e-3 H 0.089 kg-m2 0.005 N.m.s.rad-1 0.5128 V/rad/sec Fig. 6: Electromagnetic torque Vs Time The above graph shows the variation of electromagnetic torque in Nm with respect to time. The starting value of stator electromagnetic torque is very high due to starting of the motor. The electromagnetic torque varies continuously till t 1.5 secs and then becomes constant. Three wheel drive dynamics simulation model is developed in MATLAB as shown below and workspace variables are defined. 276

International Journal of Pure and Applied Mathematics Vx omega Fz Special Issue A Fx Vehicle velocity Tire F Inertia lateral Env Fxf Vx K Fxr Fzf K Theta Fzr K Inertia lateral Rear Differenti al Drive shaft inertia B -c Inertia lateral Vx omega Fz Fx Tire RL Longitudinal Vehicle Dynamics Inclined slope A B C K Tire forces Wheel RPMs Vx omega Fz Fx C Tire RR Fig. 7: Simulation model three wheel drive dynamics The result of vehicle velocity, horizontal tire forces, vertical tire forces and wheel RPMs with respect to time is shown below. In below shown graphs the Tire F denotes the front wheel, Tire RL denotes the rear left wheel and Tire RR denotes the rear right wheel. Fig. 8: Horizontal force Vs Time From t 0 to 4.5 sec the two wheels having different Horizontal tire forces, but at 2 secs and beyond 4.5secs both have almost equal Horizontal tire forces acting on them. 277

International Journal of Pure and Applied Mathematics Special Issue Fig. 9: Vertical force Vs Time From t 0 to 5 secs the both the wheels having different Vertical tire forces. The front tire is having more Vertical force acting on it at t 0 secs and after t 2.2 secs, but beyond 4.5 secs different constant vertical tire forces acting on them. Fig. 10: Variation of vehicle velocity Vs time The variation of vehicle velocity with respect to time is shown in above graph. At t 0 sec the vehicle velocity is maximum and after it decreases linearly with respect to time and then increases linearly beyond 4.5 secs. At t 0 sec all the wheels are having zero RPM and then increase gradually with front wheel having the higher RPM and both rear wheels running with equal RPM beyond 4.5 secs. 278

International Journal of Pure and Applied Mathematics Special Issue Fig. 11: Speed vs Time 4. Conclusion The present work three-wheeled car dynamic performance and stability are investigated. As the science and technology is developing day by day and the ideas of energy conservation are being more and more popular in the society, electric car will take a greater part in people’s daily life. This paper analyse the principle of brushless DC motor used in the electric car. The brushless DC motor was modelled in MATLAB Simulink. Analysis is done, which would help the further popularization for application of the brushless DC motor for improving the vehicle performance. References [1]. T.J. Sokira and W.Jaffe, Brushless DC motors:Electronic Commutation and Control, Tab Books, USA, 1989 [2].Tay Siang Hui, K.P. Basu and V.Subbiah Permanent Magnet Brushless Motor Control Techniques, National Power and EnergyConference (PECon) 2003 Proceedings, Bangi,Malysia [3]. Nicola Bianchi,SilverioBolognani,Ji-HoonJang,Seung-Ki Sul,” Comparison of PM Motorstructures and sensor less ControlTechniques for zero-speed Rotorposition detection” IEEE transactions on powerElectronics, Vol 22, No.6, Nov 2006. [4]. P.Thirusakthimurugan, P.Dananjayan,’A NewControl Scheme for The Speed Control ofMBLDC Motor Drive’ 1-42440342-1/06/ 20.00 2006 IEEE [5]. Aga, M.; Okada, A. Analysis of vehicle stability control effectivenessfrom accident data, ESV Conference, Nagoya (2003). 279

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vehicle is used to determine the normal reaction on the front and rear wheel. The Parked vehicle dynamics are testi ng in the different road conditions i.e., level road and an inclined road. W f 2 W r m g c l1l2 L Fig. 1: Vehicle dynamics on level road Fig. 2: Parked vehicle on an inclined road